壁面粗糙度对压缩空气储能大功率轴流空气透平性能影响研究OA

Compressed air energy storage(CAES)is a key technology for large-scale power storage.As a core component for energy conversion,a high-power axial flow turbine significantly influences the overall efficiency of an energy storage station.During actual operation,changes in turbine blade surface roughness,which are caused by processing techniques and long-term wear,significantly affect the turbine performance and internal flow.However,the mechanism of the roughness influence for large-power multistage multilevel axial flow turbines with air as the working medium remains unclear.This study investigates the influence of surface roughness on the aerodynamic performance and internal flow characteristics of a high-power,three-stage multilevel axial flow turbine within a 350-MW compressed air energy storage system using high-precision numerical simulation methods.The results indicate that increased surface roughness significantly reduces the mass flow rate and isentropic efficiency of all turbine stages,with the first stage exhibiting the most significant efficiency reduction.Surface roughness intensifies flow losses by thickening the suction-side boundary layer,expanding the chordwise low-speed zone on the blade,and diminishing the kinetic energy within the high-speed core region of the flow field.The performance of the first-stage turbine was more significantly affected by roughness than that of the second and third stages.As the roughness increased,the intensity of the blade surface vorticity weakened,and the separation point moved upstream.This study reveals the influence law of wall roughness on the performance of multistage turbines,providing a theoretical basis for high-precision aerodynamic design,surface process control,and operation and maintenance strategies for high-power axial-flow turbines in CAES power stations.